1. Field Of The Invention
This invention is in the field of recording and reproduction apparatus and methods for effecting high density bit type recordings on record members such as cards, tapes and discs. Recording densities are substantially enhanced by varying either the angles of elongated magnetic or electro-optically scannable recordings provided at select recording locations of a record track or variably shaping and discriminating, upon reproduction thereof, the configurations of the bit recordings along a record track of a record member.
2. The Prior Art
The prior art consists of magnetic recording systems in which a transducer effects the recording of magnetic domains along a record track of a magnetic recording material, wherein each of the domains so formed extends in a given direction. In the case of electro-optically scannable recordings, such have been provided in the configuration of elongated pits or cavities which extend parallel to the recording axis of the record track and/or directly therealong.
3. Summary Of The Invention
This invention relates to an apparatus and method for transducing information with respect to select tracks of a record member, such as a record card, tape or disc, and particularly to improvements in apparatus for recording on and reading same employing magnetic and/or radiation-electro-optical recording and reading means.
In conventional recording employing a magnetic recording member, such as a tape, disc or card, or a member which is radiation sensitive, bit recordings of information are effected by either magnetic domains which are formed parallel to each other by magnetic fields generated across the recording gap of magnetic recording transducer or, in the case of optical recordings, by pulsing a laser beam directed at a record track of a record member, in a manner to vaporize and form an elongated cavity or pit extending parallel to the record track. Such domains or cavities are provided at spaced-apart locations of the record track of the record member and each defines a bit or pulse recording which extends at the same angle to the record track as the other bit or pulse recordings to provide, for example, the binary notations "0" or "1". The result is a binary-type series of recordings extending longitudinally along the record track, each of which bit or pulse recordings defines a particular program or information recorded in coded digital form. Such digital recordings are provided as discrete magnetic domains, elongated cavities or otherwise formed electro-optically scannable spots when the recording transducer is pulsed and its magnetic field or radiation is aligned with the record track along which the recording is effected. Such signal recording is effected in a manner whereby recording densities of between 20,000 and 40,000 bits per inch may be achieved without difficulty utilizing magnetic transducers of conventional design.
The instant invention provides means for substantially increasing such recording density by what is termed herein as "overlap-recording," a process in which two or more recordings of data, such as digital data, are provided along the same length of the same record track or along very closely spaced record tracks with very little, if any, guard band areas therebetween, wherein each recording is composed of respective longitudinal arrays of parallel magnetic domains or elongated cavities which overlap or extend close to the domains or cavities of the other recordings. By differently angling and/or overlapping the magnetic domains or elongated cavities of each recording, they may be separately discriminated by a suitable similarly angled magnetic pick-up or a suitable electro-optical detector or series of detectors, thus providing two or more different recordings along the same length of record track.
Accordingly it is a primary object of this invention to provide new and improved recording systems and methods for recording two or more recordings along the same length of the same track of a record member.
Another object is to provide a recording system and method employing one or more recording and/or reproduction transducers which may be controllably pivoted about their central axes to selectively align them with a select track of a record member so as to selectively record along and/or read from such select track.
Another object is to provide a new and improved high density electro-optical recording and reproduction system and method employing recordings of code or byte-defining information in the form of microminiature indicia of substantially the same scale or size but different in shape.
Another object is to provide a high density electro-optical recording and reproduction system and method employing recordings of code or byte-defining information defined by microminiature narrow elongated indicia which vary in orientation with respect to the axis of a record track wherein the specific orientation of each indicia, when detected, is an indication of a specific or select byte of data or code.
Another object is to provide a high density electro-optical recording and reproduction system which has a substantially greater recording density than the density of conventional pulsed laser beam recording methods.
Another object is to provide a high density electro-optical recording arrangement employing means for recording indicia of different select shapes.
Another object is to provide a high density electro-optical recording arrangement for recording spot-like areas of the same shape but differently oriented.
With the above and such other objects in view as may hereinafter more fully appear, the invention consists of the novel constructions, combinations and arrangements of parts as will be more fully described and illustrated in the accompanying drawings, but it is to be understood that changes, variations and modifications may be resorted to which fall within the scope of the invention as claimed.